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Abstract:

A metallic structure and an opto-electronic apparatus are provided. The
metallic structure is used for filtering or polarizing an electromagnetic
wave, and includes a light-permissible medium, a first metallic block and
a second metallic block. The first and second metallic blocks are
parallel to and spaced from each other at a predetermined distance (d),
and are disposed inside or over the light-permissible medium. After
passing through the metallic structure, the electromagnetic wave has a
distribution curve of transmittance versus wavelength, wherein the
distribution curve has at least one transmittance peak value
corresponding to at least one wavelength in a one-to-one manner. The
aforementioned predetermined distance (d) and an averaged width of the
first metallic block satisfy the following relationships: d<λ;
0.01λ<w<d, wherein λ represents one of the
aforementioned at least one wavelength.

Claims:

1. A metallic structure for filtering or polarizing an electromagnetic
wave, the metallic structure comprising: a light-permissible medium; a
first metallic block disposed inside or over the light-permissible
medium; and a second metallic block disposed inside or over the
light-permissible medium, wherein the first metallic block and the second
metallic block are parallel to and spaced from each other at a
predetermined distance, wherein the electromagnetic wave is incident on
the first metallic block and the second metallic block and into between
the first metallic block and the second metallic block, and after passing
through the metallic structure, the electromagnetic wave has a
distribution curve of transmittance versus wavelength, wherein the
distribution curve has at least one transmittance peak value
corresponding to at least one wavelength in a one-to-one manner, the
predetermined distance and an averaged width of the first metallic block
satisfying the following relationships: d<λ;
0.01.lamda.<w<d, where d represents the predetermined distance;
λ represents one of the at least one wavelength; w represents an
averaged width of the first metallic block.

2. The metallic structure as claimed in claim 1, wherein the
predetermined distance and the averaged width of the first metallic block
satisfying the following relationship: d+w<λ.

3. The metallic structure as claimed in claim 1, wherein an averaged
length of the first metallic block satisfying the following relationship:
1<2.lamda., wherein 1 represents the averaged length of the first
metallic block.

4. The metallic structure as claimed in claim 1, wherein λ is
corresponding to one of the at least one transmittance peak value, and
the one of at least one transmittance peak value is a first transmittance
peak value, and the first transmittance peak value is greater than 10%,
and a spectrum half width corresponding to between the wavelength of the
first transmittance peak value and the wavelength whose transmittance is
70% of the first transmittance peak value is smaller than 2.lamda./3.

5. The metallic structure as claimed in claim 1, wherein the
electromagnetic wave comprises a range wavelength which is substantially
between 0.1 μm and 12 μm.

6. The metallic structure as claimed in claim 1, further comprising: a
third metallic block which is disposed inside or over the
light-permissible medium and is adjacent to one side of the first
metallic block and the second metallic block.

7. The metallic structure as claimed in claim 6, wherein the third
metallic block does not simultaneously contact the first metallic block
and the second metallic block.

8. The metallic structure as claimed in claim 6, wherein an extension of
the third metallic block is substantially perpendicular to extensions of
the first metallic block and the second metallic block.

9. The metallic structure as claimed in claim 6, further comprising: a
fourth metallic block which is disposed inside or over the
light-permissible medium and is adjacent to the other side of the first
metallic block and the second metallic block.

10. The metallic structure as claimed in claim 9, wherein the fourth
metallic block does not simultaneously contact the first metallic block
and the second metallic block.

11. The metallic structure as claimed in claim 9, wherein an extension of
the fourth metallic block is substantially perpendicular to extensions of
the first metallic block and the second metallic block.

12. The metallic structure as claimed in claim 9, wherein the fourth
metallic block is spaced from the third metallic block at a distance
smaller than 2.lamda..

13. The metallic structure as claimed in claim 9, further comprising: a
metallic frame disposed inside or over the light-permissible medium,
wherein the first metallic block, the second metallic block, the third
metallic block or the fourth metallic block is disposed inside or
overlapped with the metallic frame.

14. A metallic structure for filtering or polarizing an electromagnetic
wave, the metallic structure comprising: a light-permissible medium; a
metallic array disposed inside or over the light-permissible medium, the
metallic array comprising a plurality array units, each of the metallic
array units comprising: a first metallic block; and a second metallic
block which is parallel to and spaced from the first metallic block at a
predetermined distance, wherein the electromagnetic wave is incident on
the first metallic block and the second metallic block and into between
the first metallic block and the second metallic block, and after passing
through the metallic structure, the electromagnetic wave has a
distribution curve of transmittance versus wavelength, wherein the
distribution curve has at least one transmittance peak value
corresponding to at least one wavelength in a one-to-one manner, the
predetermined distance and an averaged width of the first metallic block
satisfying the following relationships: d<λ;
0.01.lamda.<w<d, where d represents the predetermined distance;
λ represents one of the at least one wavelength; w represents an
averaged width of the first metallic block.

15. The metallic structure as claimed in claim 14, wherein the
predetermined distance and the averaged width of the first metallic block
satisfying the following relationship: d+w<λ.

16. The metallic structure as claimed in claim 14, wherein an averaged
length of the first metallic block satisfying the following relationship:
1<2.lamda., wherein 1 represents the averaged length of the first
metallic block.

17. The metallic structure as claimed in claim 14, wherein λ is
corresponding to one of the at least one transmittance peak value, and
the one of at least one transmittance peak value is a first transmittance
peak value, and the first transmittance peak value is greater than 10%,
and a spectrum half width corresponding to between the wavelength of the
first transmittance peak value and the wavelength whose transmittance is
70% of the first transmittance peak value is smaller than 2.lamda./3.

18. The metallic structure as claimed in claim 14, wherein the
electromagnetic wave comprises a range wavelength which is substantially
between 0.1 μm and 12 μm.

19. The metallic structure as claimed in claim 14, wherein at least one
of the metallic array units further comprises: a third metallic block
which is disposed inside or over the light-permissible medium and is
adjacent to one side of the first metallic block and the second metallic
block.

20. The metallic structure as claimed in claim 19, wherein the third
metallic block does not simultaneously contact the first metallic block
and the second metallic block.

21. The metallic structure as claimed in claim 19, wherein the at least
one of the metallic array units further comprises: a fourth metallic
block which is disposed inside or over the light-permissible medium and
is adjacent to the other side of the first metallic block and the second
metallic block.

22. The metallic structure as claimed in claim 21, wherein the fourth
metallic block does not simultaneously contact the first metallic block
and the second metallic block.

23. The metallic structure as claimed in claim 21, wherein an extension
of the third metallic block or the fourth metallic block is substantially
perpendicular to extensions of the first metallic block and the second
metallic block.

24. The metallic structure as claimed in claim 21, further comprising: a
metallic frame disposed inside or over the light-permissible medium,
wherein the first metallic block, the second metallic block, the third
metallic block or the fourth metallic block is disposed inside or
overlapped with the metallic frame.

25. An opto-electronic apparatus, comprising: a metallic structure as
claimed in claim 1.

26. An opto-electronic apparatus, comprising: a metallic structure as
claimed in claim 14.

Description:

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the priority benefit of Taiwan Application
serial no. 100142940, filed on Nov. 23, 2011, the full disclosures of
which are incorporated herein by reference.

BACKGROUND

[0002] 1. Field of Invention

[0003] The present invention relates to a metallic structure and an
opto-electronic apparatus. More particularly, the present invention
relates to metallic structure and an opto-electronic apparatus for
filtering and/or polarizing an electromagnetic wave.

[0004] 2. Description of Related Art

[0005] Filtering of specific frequency spectrum and polarization are basic
operations on electromagnetic waves. The materials and devices capable of
color filtering and polarization provide important functionality in
electro-optical systems, and are often critical parts of electro-optical
systems for scientific, engineering, industrial, consumer, defense and
many other applications. The peak transmission efficiency and the
effective narrowing of the transmission spectrum are important factors
for these applications.

[0006] The materials used by conventional skills are mostly dielectrics
capable of interacting with electromagnetic waves such as dye, organic,
plastic, etc., and are often in a form of film. Since decades ago, a net
of metal wires were found to be capable of filtering waves within
microwave frequency range, and recently has been improved up to far
inferred.

[0007] Recently, it is found by scientists that the transmittance of
electromagnetic waves can be enhanced through subwavelength holes in the
metal film. Although the intensity of electromagnetic waves transmitted
through the holes can be higher than that impinging on the area of the
holes, yet the overall transmitted intensity is only a small fraction
(e.g., less than 10%) of the incoming electromagnetic waves partially
because the area of the holes is much smaller than the overall area
irradiated by the incoming waves.

SUMMARY

[0008] Therefore, an object of the present invention is to provide a
metallic structure for increasing the transmittance of an electromagnetic
wave or effectively polarizing or filtering the electromagnetic wave.

[0009] According to the aforementioned object, an aspect of the present
invention is to provide a metallic structure for filtering (or splitting)
or polarizing an electromagnetic wave. The metallic structure includes a
light-permissible medium, a first metallic block, a second metallic
block. The first metallic block is disposed inside or over the
light-permissible medium. The second metallic block is disposed inside or
over the light-permissible medium, wherein the first metallic block and
the second metallic block are substantially parallel to and spaced from
each other at a predetermined distance. The electromagnetic wave is
incident on the first metallic block and the second metallic block and
into between the first metallic block and the second metallic block.
After passing through the metallic structure, the electromagnetic wave
has a distribution curve of transmittance versus wavelength, wherein the
distribution curve has at least one transmittance peak value
corresponding to at least one wavelength in a one-to-one manner. The
aforementioned predetermined distance and an averaged width of the first
metallic block satisfies the following relationships: d<λ;
0.01λ<w<d, where d represents the aforementioned
predetermined distance; λ represents one of the aforementioned at
least one wavelength; w represents an averaged width of the first
metallic block.

[0010] In another embodiment, the aforementioned predetermined distance
and the averaged width of the first metallic block satisfies the
following relationship: d+w<λ.

[0011] In another embodiment, an averaged length of the first metallic
block satisfies the following relationship 1<2λ, wherein 1
represents the averaged length of the first metallic block.

[0012] In another embodiment, λ is corresponding to one (referred to
as a first transmittance peak value hereinafter) of the aforementioned at
least one transmittance peak value, and the first transmittance peak
value is greater than 10%, and a spectrum half width corresponding to
between the wavelength of the first transmittance peak value and the
wavelength whose transmittance is 70% of the first transmittance peak
value is smaller than 2λ/3.

[0013] In another embodiment, the aforementioned electromagnetic wave
includes a range wavelength which is substantially between 0.1 μm and
12 μm.

[0014] In another embodiment, the aforementioned metallic structure
further includes a third metallic block which is disposed inside or over
the light-permissible medium and is adjacent to one side of the first
metallic block and the second metallic block.

[0015] In another embodiment, the aforementioned third metallic block does
not simultaneously contact the first metallic block and the second
metallic block.

[0016] In another embodiment, an extension of the aforementioned third
metallic block is substantially perpendicular to extensions of the first
metallic block and the second metallic block.

[0017] In another embodiment, the aforementioned metallic structure
further includes a fourth metallic block which is disposed inside or over
the light-permissible medium and is adjacent to the other side of the
first metallic block and the second metallic block.

[0018] In another embodiment, the aforementioned fourth metallic block
does not simultaneously contact the first metallic block and the second
metallic block.

[0019] In another embodiment, an extension of the aforementioned fourth
metallic block is substantially perpendicular to extensions of the first
metallic block and the second metallic block.

[0020] In another embodiment, the aforementioned fourth metallic block is
spaced from the third metallic block at a distance smaller than 2λ.

[0021] In another embodiment, the aforementioned metallic structure
further includes a metallic frame disposed inside or over the
light-permissible medium, wherein the first metallic block, the second
metallic block, the third metallic block and the fourth metallic block is
disposed inside or overlapped with the metallic frame.

[0022] According to the aforementioned object, another metallic structure
is provided to polarize or to filter an electromagnetic wave. This
metallic structure includes a light-permissible medium and a metallic
array. The metallic array is disposed inside or over the
light-permissible medium, and the metallic array includes a plurality
array units. Each of the metallic array units includes the aforementioned
first metallic block and the aforementioned second metallic block.

[0023] In another embodiment, at least one of the aforementioned metallic
array units includes the aforementioned third metallic block.

[0024] In another embodiment, the aforementioned at least one of the
aforementioned metallic array units includes the aforementioned fourth
metallic block.

[0025] In another embodiment, the aforementioned at least one of the
aforementioned metallic array units includes the aforementioned metallic
frame.

[0026] Furthermore, another aspect of the present invention is to provide
an opto-electronic apparatus (e.g. a display device) including one of the
aforementioned metallic structure.

[0027] With the applications of the aforementioned embodiments, the
transmittance of the electromagnetic wave can be increased or the
electromagnetic wave can be effectively polarized.

[0028] It is to be understood that both the foregoing general description
and the following detailed description are examples, and are intended to
provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] These and other features, aspects, and advantages of the present
invention will become better understood with regard to the following
description, appended claims, and accompanying drawings where:

[0030] FIG. 1A is schematic 3-D diagram of a metallic structure according
to a first embodiment of the present invention;

[0031] FIG. 1B is a schematic top view of the metallic structure according
to a first example and a second example of applying the first embodiment;

[0032] FIG. 1C is a schematic top view of the metallic structure according
to a third example of applying the first embodiment;

[0033] FIG. 1D is a schematic top view of the metallic structure according
to a fourth example of applying the first embodiment;

[0034] FIG. 1E is a schematic top view of the metallic structure according
to a fifth example of applying the first embodiment;

[0035]FIG. 2A shows distribution curves of x-axis transmittance versus
wavelength obtained by simulating the first to fifth examples of applying
the first embodiment;

[0036]FIG. 2B shows distribution curves of z-axis transmittance versus
wavelength obtained by simulating the first to fifth examples of applying
the first embodiment;

[0037] FIG. 3A is schematic top view of a metallic structure according to
a first example of applying a second embodiment of the present invention;

[0038]FIG. 3B is a schematic top view of the metallic structure according
to a second example of applying the second embodiment;

[0039] FIG. 3C is a schematic top view of the metallic structure according
to a third example of applying the second embodiment;

[0040]FIG. 3D is a schematic top view of the metallic structure according
to a fourth example of applying the second embodiment;

[0041] FIG. 4A shows distribution curves of x-axis transmittance versus
wavelength obtained by simulating the first to fourth examples of
applying the second embodiment;

[0042] FIG. 4B shows distribution curves of z-axis transmittance versus
wavelength obtained by simulating the first to fourth examples of
applying the second embodiment;

[0043] FIG. 5A is schematic top view of a metallic structure according to
a first example of applying a third embodiment of the present invention;

[0044]FIG. 5B is a schematic top view of the metallic structure according
to a second example of applying the third embodiment;

[0045] FIG. 5C is a schematic top view of the metallic structure according
to a third example of applying the third embodiment;

[0046] FIG. 5D is a schematic top view of the metallic structure according
to a fourth example of applying the third embodiment;

[0047] FIG. 5E is a schematic top view of the metallic structure according
to a fifth example of applying the third embodiment;

[0048] FIG. 5F is a schematic top view of the metallic structure according
to a sixth example of applying the third embodiment;

[0049] FIG. 5G is a schematic top view of the metallic structure according
to a seventh example of applying the third embodiment;

[0050] FIG. 6A shows distribution curves of x-axis transmittance versus
wavelength obtained by simulating the first to seventh examples of
applying the third embodiment;

[0051] FIG. 6B shows distribution curves of z-axis transmittance versus
wavelength obtained by simulating the first to seventh examples of
applying the third embodiment;

[0052] FIG. 7A is schematic top view of a metallic structure according to
an example of applying a fourth embodiment of the present invention;

[0058] Reference will now be made in detail to the present preferred
embodiments of the invention, examples of which are illustrated in the
accompanying drawings. Wherever possible, the same reference numbers are
used in the drawings and the description to refer to the same or like
parts.

[0059] Electrons on the surface of metallic materials can strongly
interact with electromagnetic fields, depending on its polarization. In
fact, the collective electron motions have plasmonic eigenmodes of which
the frequency is proportional to the square root of the electron density
that is higher for regular metals and lower for doped semiconductors. A
typical plasmonic frequency is in the range from ultraviolet to infrared.

[0060] The present invention utilizes the aforementioned interaction to
achieve good filtering and polarization as well as high transmission
efficiency. Electromagnetic force is a long range force, so that the
aforementioned interaction does not require a physical contact. Although
the multiple metallic blocks or sheets disposed inside or over the
light-permissible medium may or may not contact each other, the electrons
on one metallic block or sheet can interact with the electromagnetic wave
fields which at the same time also interact with the electrons on another
block or sheet nearby. These coupled interactions can occur even when
there is no physical contact between two blocks/sheets, allowing the
surface plasmons to propagate (or the electrons and the electron
oscillations to flow) from one block/sheet to another block/sheet. The
electric field of the electromagnetic wave has a component (vertically
polarized wave) perpendicular to the boundary of the block/sheet, and a
component (parallel polarized wave) parallel to the boundary of the
block/sheet. These coupled interactions through the electric field can be
further enhanced by the polarization effect induced at the boundary
surface of the blocks/sheets. The metallic block of the present invention
is referred to a square block, a rectangular block or a block in another
shape formed from a metallic material. The metallic material is referred
to a metal material or a material with partial metallic characters,
wherein the metal material can be such as copper, aluminum, alloy, etc.,
and the material with partial metallic characters can be such as a
semiconductor material or a mixture containing the semiconductor
material. The light-permissible medium of the present invention can be
any light-permissible material, such as air, glass, dielectric, etc.

[0061] When the medium (such as the boundary or width of the metallic
block) is changed, the electron oscillations will be reflected or
partially reflected. The electron oscillations will vigorously interact
with the parallel and perpendicular polarized waves, and respectively
affect the transmission and reflection of the parallel and perpendicular
polarized waves. The geometrical changes of the metallic blocks (such as
the changes of respective lengths, widths and thickness thereof) can all
affect the electron oscillations and the interactions with the parallel
and perpendicular polarized waves of light, and thus affect the
transmission, filtering and polarization of light, wherein the
interactions can be understood by a finite-difference time-domain (FDTD)
simulation.

[0062] On the other hand, a metallic structure of the preset invention is
applicable to an opto-electronic apparatus such as a filter, a polarizer,
a wave splitter, a sensor or a display, etc. The metallic structure of
the present invention is used for filtering (splitter) or polarizing an
electromagnetic wave, wherein the electromagnetic wave includes a
preferable range wavelength which is substantially between 0.1 μm and
12 μm, and more preferably, substantially between 0.1 μm and 2
μm (as shown in the following simulation results). However, the
wavelength range of the electromagnetic wave which can be processed by
the metallic structure of the present invention is not limited thereto,
and may be the wavelength within any range.

[0063] Hereinafter, several embodiments are illustrated for explaining
metallic structures of the present invention, wherein metallic blocks
forming the metallic structures used in examples corresponding to
respective embodiments are formed from Al--Cu alloy, and a
light-permissible medium used in each example is air, and the metallic
blocks can be fixed on an opto-electronic apparatus by means of an
appropriate mechanism. In the following embodiments, same reference
numbers shown in the figures represent same or similar elements.

First Embodiment

[0064] Referring to FIG. 1A and FIG. 1B, FIG. 1A is schematic 3-D diagram
of a metallic structure according to a first embodiment of the present
invention, and FIG. 1B is a schematic top view of the metallic structure
according to a first example and a second example of applying the first
embodiment. The first embodiment is a basic metallic structure of the
present invention, and for convenience of explanation, a
light-permissible medium 100 is omitted in FIG. 1A. As shown in FIG. 1A,
the basic metallic structure of the present invention is formed from two
substantially parallel metallic blocks, including a first metallic block
110 and a second metallic block 120, used for filtering or polarizing an
electromagnetic wave. As shown in FIG. 1B, the first metallic block 110
and the second metallic block 120 are disposed inside or over a surface
of the light-permissible medium 100, wherein the size of the
light-permissible medium 100 is merely used as an example for
explanation, and do not intend to limit embodiments of the present
invention. In fact, the size of the light-permissible medium 100 may be
adjusted in accordance with actual needs. Furthermore, if
light-permissible medium 100 fails to provide support to the metallic
structure, an appropriate support mechanism is required to be designed
additionally, which is well known to those who are skilled in the art and
not described herein.

[0065] The first metallic block 110 and the second metallic block 120 are
spaced from each other at a predetermined distance d, wherein the
electromagnetic wave is incident on surfaces of the first metallic block
110 and the second metallic block 120 and between the first metallic
block 110 and the second metallic block 120.

[0066] As shown in FIG. 2A and FIG. 2B, after passing through the metallic
structure, the electromagnetic wave has a distribution curve of
transmittance versus wavelength, wherein the distribution curve has at
least one transmittance peak value corresponding to at least one
wavelength in a one-to-one manner. The predetermined distance d and an
averaged width w1 of the first metallic block 110 satisfies the following
relationships:

d<λ (1)

0.01λ<w1<d (2)

[0067] where λ represents one of the at least one wavelength.

[0068] The predetermined distance d and the averaged width w1 of the first
metallic block 110 also satisfy the following relationship:

d+w1<λ (3)

[0069] An averaged length 11 of the first metallic block 110 satisfies the
following relationship:

11<2λ (4)

[0070] Furthermore, λ is corresponding to one (a first transmittance
peak value) of the at least one transmittance peak value, and the first
transmittance peak value is greater than 10%, and a spectrum half width
corresponding to between the wavelength of the first transmittance peak
value and the wavelength whose transmittance is 70% of the first
transmittance peak value is smaller than 2λ/3. It is worthy of
being noted that λ is a wavelength desired to be obtained by
performing a filtering operation using the metallic structure of the
present invention, such as red light wavelength, green light wavelength
or blue light wavelength, etc.

[0071] As shown in FIG. 1B, a transmittance is a ratio of the intensities
of the electromagnetic wave before or after entering an area Ac between
the second metallic block 120 and the first metallic block 110 plus an
area Ab of the first metallic block 110. Since the predetermined distance
d is smaller than λ, electrons or plasmons on the second metallic
block 120 and the first metallic block 110 are coupled with the electric
field of the electromagnetic wave, such that the metallic structure of
the present invention has excellent filtering and polarizing effects. The
transmittance can be divided into a component (referred as a x-axis
transmittance, as shown in FIG. 2A) passing through an electric field
along the x axis (substantially perpendicular to the longitudinal
direction of the second metallic block 120 and the first metallic block
110), and a component (referred as a z-axis transmittance, as shown in
FIG. 2B) passing through an electric field along the z axis
(substantially parallel to the longitudinal direction of the second
metallic block 120 and the first metallic block 110). From the
distribution curves of x-axis transmittance versus wavelength and those
of z-axis transmittance versus wavelength, the filtering and polarizing
effects of the metallic structure of this embodiment can be known,
wherein the x-axis transmittance component and the z-axis transmittance
component may exhibit the polarizing effect of the metallic structure,
and the transmittance at a peak value, a valley value or zero may exhibit
the filtering effect. When the transmittance is at a peak value, it means
that the electromagnetic wave with a wavelength corresponding to the
transmittance can pass through the metallic structure. When the
transmittance is at a valley value or zero, it means that the
electromagnetic wave with a wavelength corresponding to the transmittance
is filtered out by the metallic structure. In the following, examples of
applying the first embodiment are illustrated for explanation. Referring
to FIG. 2A and FIG. 2B, FIG. 2A shows distribution curves of x-axis
transmittance versus wavelength obtained by simulating the first to fifth
examples of applying the first embodiment, and FIG. 2B shows distribution
curves of z-axis transmittance versus wavelength obtained by simulating
first to fifth examples of applying the first embodiment.

FIRST EXAMPLE

[0072] In this example, the length 11 of the first metallic block 110 is
0.32 μm; the width w1 thereof is 0.16 μm; and the thickness t1
thereof is 0.08 μm. The length 12 of the second metallic block 120 is
0.32 μm; the width w2 thereof is 0.16 μm; and the thickness t2
thereof is 0.08 μm. The predetermined distance d between the first
metallic block 110 and the second metallic block 120 is 0.32 μm.

[0073] As shown in FIG. 2A, the curve corresponding to the first example
has a plurality of transmittance peak values. At a transmittance peak
value of 140%, the wavelength λ corresponding thereto is 1.4 μm,
and thus the length 11, the width w1 of the first metallic block 110, and
the predetermined distance d satisfy the aforementioned equations
(1)-(4). Furthermore, the spectrum half width (1.4 μm-1.1 μm=0.3
μm) corresponding to between the wavelength of the first transmittance
peak value (140%) and the wavelength whose transmittance is 70% of the
first transmittance peak value (140%×0.7=98%) is also smaller than
2λ/3 (0.93 μm).

[0074] As shown in FIG. 2B, the curve corresponding to the first example
has many transmittance peak values. At a transmittance peak value of 46%,
the wavelength λ corresponding thereto is 1.45 μm, and thus the
length 11 and the width w1 of the first metallic block 110, and hence the
predetermined distance d satisfy the aforementioned equations (1)-(4).
Furthermore, the spectrum half width (1.45 μm-1.25 μm=0.2 μm)
corresponding to between the wavelength of the first transmittance peak
value (46%) and the wavelength whose transmittance is 70% of the first
transmittance peak value (46%×0.7=32.2%) is also smaller than
2λ/3 (0.96 μm). At a transmittance peak value of 0%, the
wavelength λ corresponding thereto is 0.8 μm, which is about
equal to twice of the length 11 (0.32 μm), in which the phenomenon is
relevant to the surface plasmons discussed above.

[0075] From FIG. 2A and FIG. 2B, it can be known that the metallic
structure of this example has good filtering and polarizing effects.

SECOND EXAMPLE

[0076] The second example is different from the first example in that the
thickness t1 of the first metallic block 110 and the thickness t2 of the
second metallic block 120 both are 0.16 μm.

[0077] From FIG. 2A and FIG. 2B, it can be known that the length 11, the
width w1 of the first metallic block 110, and the predetermined distance
d of this example satisfy the aforementioned equations (1)-(4), and the
metallic structure of this example has good filtering and polarizing
effects.

[0078] From the first example and the second example, it can be known that
different thickness of the metallic block does not greatly affect the
filtering and polarizing. The thickness of the metallic block is
generally smaller than the desired wavelength λ, but the present
invention is not limited thereto.

THIRD EXAMPLE

[0079] Referring to FIG. 1C, FIG. 1C is a schematic top view of the
metallic structure according to the third example of applying the first
embodiment. In this example, the length 11 of the first metallic block
110 is 0.32 μm; the width w1 thereof is 0.16 μm; and the thickness
t1 thereof is 0.08 μm. The length 12 of the second metallic block 120
is 4.0 μm; the width w2 thereof is 1.84 μm; and the thickness t2
thereof is 0.08 μm. The predetermined distance d between the first
metallic block 110 and the second metallic block 120 is 0.32 μm.

[0080] From FIG. 2A and FIG. 2B, it can be known that the length 11, the
width w1 of the first metallic block 110, and the predetermined distance
d of this example satisfy the aforementioned equations (1)-(4), and the
metallic structure of this example has good filtering and polarizing
effects.

FOURTH EXAMPLE

[0081] Referring to FIG. 1D, FIG. 1D is a schematic top view of the
metallic structure according to the fourth example of applying the first
embodiment. In this example, the length 11 of the first metallic block
110 is 0.32 μm; the width w1 thereof is 0.16 μm; and the thickness
t1 thereof is 0.08 μm. The length 12 of the second metallic block 120
is 0.32 μm; the width w2 thereof is 1.84 μm; and the thickness t2
thereof is 0.08 μm. The predetermined distance d between the first
metallic block 110 and the second metallic block 120 is 0.32 μm.

[0082] From FIG. 2A and FIG. 2B, it can be known that the length 11, the
width w1 of the first metallic block 110, and the predetermined distance
d of this example satisfy the aforementioned equations (1)-(4), and the
metallic structure of this example has good filtering and polarizing
effects.

FIFTH EXAMPLE

[0083] Referring to FIG. 1E, FIG. 1E is a schematic top view of the
metallic structure according to the fifth example of applying the first
embodiment, wherein the first metallic block 110 is disposed between the
second metallic block 120 and a third metallic block 130. The length 11
of the first metallic block 110 is 0.32 μm; the width w1 thereof is
0.16 μm; and the thickness t1 thereof is 0.08 μm. The length 12 of
the second metallic block 120 is 0.32 μm; the width w2 thereof is 0.16
μm; and the thickness t2 thereof is 0.08 μm. The length 13 of the
third metallic block 130 is 0.32 μm; the width w3 thereof is 0.16
μm; and the thickness t3 thereof is 0.08 μm. The predetermined
distance d between the first metallic block 110 and the second metallic
block 120 is 0.32 μm. The predetermined distance d between the first
metallic block 110 and the third metallic block 130 is 0.32 μm.

[0084] From FIG. 2A and FIG. 2B, it can be known that the length 11 and
the width w1 of the first metallic block 110, and the predetermined
distance d of this example satisfy the aforementioned equations (1)-(4);
the length 13 and the width w3 of the third metallic block 130, and the
predetermined distance d also satisfy the aforementioned equations
(1)-(4); and the metallic structure of this example has good filtering
and polarizing effects.

[0085] It can be known that from FIG. 2B, the metallic structures in the
above examples have excellent filtering and polarizing effects.

Second Embodiment

[0086] Referring to FIG. 3A, FIG. 3A is schematic top view of a metallic
structure according to a first example of applying a second embodiment of
the present invention. The second embodiment is different from the first
embodiment in that the metallic structure further includes a third
metallic block 130. The third metallic block 130 is disposed inside or
over the light-permissible medium 100 and is adjacent to one side of the
first metallic block 110 and the second metallic block 120. An extension
of the third metallic block 130 is substantially perpendicular to
extensions of the first metallic block 110 and the second metallic block
120, and the third metallic block 130 may or may not simultaneously
contact the first metallic block 110 and the second metallic block 120.

[0087] In the following, examples of applying the second embodiment are
illustrated for explanation. Referring to FIG. 4A and FIG. 4B, FIG. 4A
shows distribution curves of x-axis transmittance versus wavelength
obtained by simulating first to fourth examples of applying the second
embodiment, and FIG. 4B shows distribution curves of z-axis transmittance
versus wavelength obtained by simulating the first to fourth examples of
applying the second embodiment.

FIRST EXAMPLE

[0088] As shown in FIG. 3A, the third metallic block 130 does not contact
the first metallic block 110 and the second metallic block 120. The
length 11 of the first metallic block 110 is 0.3 μm; the width w1
thereof is 0.16 μm; and the thickness t1 thereof is 0.08 μm. The
length 12 of the second metallic block 120 is 0.3 μm; the width w2
thereof is 0.16 μm; and the thickness t2 thereof is 0.08 μm. The
length 13 of the third metallic block 130 is 0.3 μm; the width w3
thereof is 0.16 μm; and the thickness t3 thereof is 0.08 μm. The
predetermined distance d between the first metallic block 110 and the
second metallic block 120 is 0.32 μm.

[0089] From FIG. 4A and FIG. 4B, it can be known that the length 11, the
width w1 of the first metallic block 110, and the predetermined distance
d of this example satisfy the aforementioned equations (1)-(4), and the
metallic structure of this example has good filtering and polarizing
effects.

SECOND EXAMPLE

[0090] Referring to FIG. 3B, FIG. 3B is a schematic top view of the
metallic structure according to the second example of applying the second
embodiment, wherein the third metallic block 130 contacts the first
metallic block 110 but does not contact the second metallic block 120.
The length 11 of the first metallic block 110 is 0.31 μm; the width w1
thereof is 0.16 μm; and the thickness t1 thereof is 0.08 μm. The
length 12 of the second metallic block 120 is 0.3 μm; the width w2
thereof is 0.16 μm; and the thickness t2 thereof is 0.08 μm. The
length 13 of the third metallic block 130 is 0.47 μm; the width w3
thereof is 0.16 μm; and the thickness t3 thereof is 0.08 μm. The
predetermined distance d between the first metallic block 110 and the
second metallic block 120 is 0.32 μm.

[0091] From FIG. 4A and FIG. 4B, it can be known that the length 11, the
width w1 of the first metallic block 110, and the predetermined distance
d of this example satisfy the aforementioned equations (1)-(4), and the
metallic structure of this example has good filtering and polarizing
effects.

THIRD EXAMPLE

[0092] Referring to FIG. 3C, FIG. 3C is a schematic top view of the
metallic structure according to the third example of applying the second
embodiment, wherein the third metallic block 130 simultaneously contacts
the first metallic block 110 and the second metallic block 120. The
length 11 of the first metallic block 110 is 0.31 μm; the width w1
thereof is 0.16 μm; and the thickness t1 thereof is 0.08 μm. The
length 12 of the second metallic block 120 is 0.31 μm; the width w2
thereof is 0.16 μm; and the thickness t2 thereof is 0.08 μm. The
length 13 of the third metallic block 130 is 0.64 μm; the width w3
thereof is 0.16 μm; and the thickness t3 thereof is 0.08 μm. The
predetermined distance d between the first metallic block 110 and the
second metallic block 120 is 0.32 μm.

[0093] From FIG. 4A and FIG. 4B, it can be known that the length 11, the
width w1 of the first metallic block 110, and the predetermined distance
d of this example satisfy the aforementioned equations (1)-(4), and the
metallic structure of this example has good filtering and polarizing
effects.

FOURTH EXAMPLE

[0094] Referring to FIG. 3D, FIG. 3D is a schematic top view of the
metallic structure according to the fourth example of applying the second
embodiment, wherein the third metallic block 130 does not contact the
first metallic block 110 but contacts the second metallic block 120, and
the size of the second metallic block 120 and the third metallic block
130 are much greater than that of the first metallic block 110. The
length 11 of the first metallic block 110 is 0.3 μm; the width w1
thereof is 0.16 μm; and the thickness t1 thereof is 0.08 μm. The
length 12 of the second metallic block 120 is 2.16 μm; the width w2
thereof is 1.84 μm; and the thickness t2 thereof is 0.08 μm. The
length 13 of the third metallic block 130 is 4.00 μm; the width w3
thereof is 1.84 μm; and the thickness t3 thereof is 0.08 μm. The
predetermined distance d between the first metallic block 110 and the
second metallic block 120 is 0.32 μm.

[0095] From FIG. 4A and FIG. 4B, it can be known that the length 11 and
the width w1 of the first metallic block 110, and the predetermined
distance d of this example satisfy the aforementioned equations (1)-(4),
and the metallic structure of this example has good filtering and
polarizing effects.

[0096] It can be known that from FIG. 4B, the metallic structures in the
above examples have excellent filtering and polarizing effects.

Third Embodiment

[0097] Referring to FIG. 5A, FIG. 5A is schematic top view of a metallic
structure according to a first example of applying a third embodiment of
the present invention. The third embodiment is different from the second
embodiment in that the metallic structure further includes a fourth
metallic block 140. The fourth metallic block 140 is disposed inside or
over the light-permissible medium 100 and is adjacent to the other side
of the first metallic block 110 and the second metallic block 120. An
extension of the fourth metallic block 140 is substantially perpendicular
to extensions of the first metallic block 110 and the second metallic
block 120, and the fourth metallic block 140 may or may not
simultaneously contact the first metallic block 110 and the second
metallic block 120.

[0098] In the following, examples of applying the third embodiment are
illustrated for explanation. Referring to FIG. 6A and FIG. 6B, FIG. 6A
shows distribution curves of x-axis transmittance versus wavelength
obtained by simulating first to seventh examples of applying the third
embodiment, and FIG. 6B shows distribution curves of z-axis transmittance
versus wavelength obtained by simulating the first to seventh examples of
applying the third embodiment.

FIRST EXAMPLE

[0099] As shown in FIG. 5A, the third metallic block 130 and the fourth
metallic block 140 do not contact the first metallic block 110 and the
second metallic block 120, wherein the length 11 of the first metallic
block 110 is 0.3 μm; the width w1 thereof is 0.16 μm; and the
thickness t1 thereof is 0.08 μm. The length 12 of the second metallic
block 120 is 0.3 μm; the width w2 thereof is 0.16 μm; and the
thickness t2 thereof is 0.08 μm. The length 13 of the third metallic
block 130 is 0.3 μm; the width w3 thereof is 0.16 μm; and the
thickness t3 thereof is 0.08 μm. The length 14 of the fourth metallic
block 140 is 0.3 μm; the width w4 thereof is 0.16 μm; and the
thickness t4 thereof is 0.08 μm. The predetermined distance d between
the first metallic block 110 and the second metallic block 120 is 0.32
μm.

[0100] From FIG. 6A and FIG. 6B, it can be known that the length 11, the
width w1 of the first metallic block 110, and the predetermined distance
d of this example satisfy the aforementioned equations (1)-(4), and the
metallic structure of this example has good filtering and polarizing
effects. It is worthy of being noted that, since the metallic structure
of this embodiment is symmetrical to the x axis and the z axis, the
distribution curve of x-axis transmittance versus wavelength is identical
to that of z-axis transmittance versus wavelength.

SECOND EXAMPLE

[0101] Referring to FIG. 5B, FIG. 5B is a schematic top view of the
metallic structure according to the second example of applying the third
embodiment, wherein the third metallic block 130 contacts the first
metallic block 110 but does not contact the second metallic block 120,
and the fourth metallic block 140 does not contact the first metallic
block 110 and the second metallic block 120. The length 11 of the first
metallic block 110 is 0.31 μm; the width w1 thereof is 0.16 μm; and
the thickness t1 thereof is 0.08 μm. The length 12 of the second
metallic block 120 is 0.3 μm; the width w2 thereof is 0.16 μm; and
the thickness t2 thereof is 0.08 μm. The length 13 of the third
metallic block 130 is 0.47 μm; the width w3 thereof is 0.16 μm; and
the thickness t3 thereof is 0.08 μm. The length 14 of the fourth
metallic block 140 is 0.3 μm; the width w4 thereof is 0.16 μm; and
the thickness t4 thereof is 0.08 μm. The predetermined distance d
between the first metallic block 110 and the second metallic block 120 is
0.32 μm.

[0102] From FIG. 6A and FIG. 6B, it can be known that the length 11, the
width w1 of the first metallic block 110, and the predetermined distance
d of this example satisfy the aforementioned equations (1)-(4), and the
metallic structure of this example has good filtering and polarizing
effects.

THIRD EXAMPLE

[0103] Referring to FIG. 5C, FIG. 5C is a schematic top view of the
metallic structure according to the third example of applying the third
embodiment, wherein the third metallic block 130 contacts the first
metallic block 110 but does not contact the second metallic block 120,
and the fourth metallic block 140 contacts the first metallic block 110
but does not contact the second metallic block 120. The length 11 of the
first metallic block 110 is 0.32 μm; the width w1 thereof is 0.16
μm; and the thickness t1 thereof is 0.08 μm. The length 12 of the
second metallic block 120 is 0.3 μm; the width w2 thereof is 0.16
μm; and the thickness t2 thereof is 0.08 μm. The length 13 of the
third metallic block 130 is 0.47 μm; the width w3 thereof is 0.16
μm; and the thickness t3 thereof is 0.08 μm. The length 14 of the
third metallic block 130 is 0.47 μm; the width w4 thereof is 0.16
μm; and the thickness t4 thereof is 0.08 μm. The predetermined
distance d between the first metallic block 110 and the second metallic
block 120 is 0.32 μm.

[0104] From FIG. 6A and FIG. 6B, it can be known that the length 11, the
width w1 of the first metallic block 110, and the predetermined distance
d of this example satisfy the aforementioned equations (1)-(4), and the
metallic structure of this example has good filtering and polarizing
effects.

FOURTH EXAMPLE

[0105] Referring to FIG. 5D, FIG. 5D is a schematic top view of the
metallic structure according to the fourth example of applying the third
embodiment, wherein the third metallic block 130 contacts the first
metallic block 110 but does not contact the second metallic block 120,
and the fourth metallic block 140 does not contact the first metallic
block 110 but contacts the second metallic block 120. The length 11 of
the first metallic block 110 is 0.31 μm; the width w1 thereof is 0.16
μm; and the thickness t1 thereof is 0.08 μm. The length 12 of the
second metallic block 120 is 0.31 μm; the width w2 thereof is 0.16
μm; and the thickness t2 thereof is 0.08 μm. The length 13 of the
third metallic block 130 is 0.47 μm; the width w3 thereof is 0.16
μm; and the thickness t3 thereof is 0.08 μm. The length 14 of the
third metallic block 130 is 0.47 μm; the width w4 thereof is 0.16
μm; and the thickness t4 thereof is 0.08 μm. The predetermined
distance d between the first metallic block 110 and the second metallic
block 120 is 0.32 μm.

[0106] From FIG. 6A and FIG. 6B, it can be known that the length 11, the
width w1 of the first metallic block 110, and the predetermined distance
d of this example satisfy the aforementioned equations (1)-(4), and the
metallic structure of this example has good filtering and polarizing
effects. It is worthy of being noted that, since the metallic structure
of this embodiment is symmetrical to its center point, the distribution
curve of x-axis transmittance versus wavelength is identical to that of
z-axis transmittance versus wavelength.

FIFTH EXAMPLE

[0107] Referring to FIG. 5E, FIG. 5E is a schematic top view of the
metallic structure according to the fifth example of applying the third
embodiment, wherein the third metallic block 130 contacts the first
metallic block 110 and the second metallic block 120, and the fourth
metallic block 140 contacts the first metallic block 110 but does not
contact the second metallic block 120. The length 11 of the first
metallic block 110 is 0.32 μm; the width w1 thereof is 0.16 μm; and
the thickness t1 thereof is 0.08 μm. The length 12 of the second
metallic block 120 is 0.31 μm; the width w2 thereof is 0.16 μm; and
the thickness t2 thereof is 0.08 μm. The length 13 of the third
metallic block 130 is 0.64 μm; the width w3 thereof is 0.16 μm; and
the thickness t3 thereof is 0.08 μm. The length 14 of the third
metallic block 130 is 0.47 μm; the width w4 thereof is 0.16 μm; and
the thickness t4 thereof is 0.08 μm. The predetermined distance d
between the first metallic block 110 and the second metallic block 120 is
0.32 μm.

[0108] From FIG. 6A and FIG. 6B, it can be known that the length 11, the
width w1 of the first metallic block 110, and the predetermined distance
d of this example satisfy the aforementioned equations (1)-(4), and the
metallic structure of this example has good filtering and polarizing
effects. It is worthy of being noted that, since the metallic structure
of this embodiment is symmetrical to its center point, the distribution
curve of x-axis transmittance versus wavelength is identical to that of
z-axis transmittance versus wavelength.

SIXTH EXAMPLE

[0109] Referring to FIG. 5F, FIG. 5F is a schematic top view of the
metallic structure according to the sixth example of applying the third
embodiment, wherein the third metallic block 130 and the fourth metallic
block 140 simultaneously contact the first metallic block 110 and the
second metallic block 120. The length 11 of the first metallic block 110
is 0.32 μm; the width w1 thereof is 0.16 μm; and the thickness t1
thereof is 0.08 μm. The length 12 of the second metallic block 120 is
0.32 μm; the width w2 thereof is 0.16 μm; and the thickness t2
thereof is 0.08 μm. The length 13 of the third metallic block 130 is
0.64 μm; the width w3 thereof is 0.16 μm; and the thickness t3
thereof is 0.08 μm. The length 14 of the third metallic block 130 is
0.64 μm; the width w4 thereof is 0.16 μm; and the thickness t4
thereof is 0.08 μm. The predetermined distance d between the first
metallic block 110 and the second metallic block 120 is 0.32 μm.

[0110] From FIG. 6A and FIG. 6B, it can be known that the length 11, the
width w1 of the first metallic block 110, and the predetermined distance
d of this example satisfy the aforementioned equations (1)-(4), and the
metallic structure of this example has good filtering and polarizing
effects. It is worthy of being noted that, since the metallic structure
of this embodiment is symmetrical to its center point, the distribution
curve of x-axis transmittance versus wavelength is identical to that of
z-axis transmittance versus wavelength.

SEVENTH EXAMPLE

[0111] Referring to FIG. 5G, FIG. 5G is a schematic top view of the
metallic structure according to the seventh example of applying the third
embodiment, wherein the third metallic block 130 and the fourth metallic
block 140 do not contact the first metallic block 110 but contact the
second metallic block 120, and the size of the second metallic block 120,
the third metallic block 130, and the forth metallic block are much
greater than that of the first metallic block 110. The length 11 of the
first metallic block 110 is 0.6 μm; the width w1 thereof is 0.16
μm; and the thickness t1 thereof is 0.08 μm. The length 12 of the
second metallic block 120 is 0.64 μm; the width w2 thereof is 1.84
μm; and the thickness t2 thereof is 0.08 μm. The length 13 of the
third metallic block 130 is 4.00 μm; the width w3 thereof is 1.68
μm; and the thickness t3 thereof is 0.08 μm. The length 14 of the
third metallic block 130 is 4.00 μm; the width w4 thereof is 1.68
μm; and the thickness t4 thereof is 0.08 μm. The predetermined
distance d between the first metallic block 110 and the second metallic
block 120 is 0.32 μm.

[0112] From FIG. 6A and FIG. 6B, it can be known that the length 11, the
width w1 of the first metallic block 110, and the predetermined distance
d of this example satisfy the aforementioned equations (1)-(4), and the
metallic structure of this example has good filtering and polarizing
effects.

Fourth Embodiment

[0113] Each of the aforementioned metallic structures of the respective
embodiments (examples) can be repetitively formed as a metallic array
including a plurality of array units. Each array unit includes the
aforementioned first metallic block, the aforementioned second metallic
block, and/or the aforementioned third metallic block and/or the
aforementioned first metallic block. These metallic blocks also can be
arranged in the respective patterns shown in the aforementioned
embodiments (examples). Hereinafter, the metallic structure shown in the
first example of the third embodiment is used again for explaining the
metallic array.

[0114] Referring to FIG. 7A, FIG. 7A is schematic top view of a metallic
structure according to an example of applying a fourth embodiment of the
present invention, wherein the metallic array includes a plurality of
metallic units 200, and each metallic unit 200 includes the first,
second, third, and fourth metallic blocks shown in the first example of
applying the third embodiment.

[0116] From FIG. 7B and FIG. 7C, it can be known that the length 11, the
width w1 of the first metallic block 110, and the predetermined distance
d of this example satisfy the aforementioned equations (1)-(4), and the
metallic structure of this example has good filtering and polarizing
effects.

Fifth Embodiment

[0117] Each of the aforementioned metallic structures of the respective
embodiments (examples) can be disposed in a metallic frame formed from a
metallic material. A metallic structure of this embodiment includes the
aforementioned first metallic block, the aforementioned second metallic
block, and/or the aforementioned third metallic block and/or the
aforementioned forth metallic block. These metallic blocks also can be
arranged in the respective patterns shown in the aforementioned
embodiments (examples). Hereinafter, disposing the metallic structure
shown in the first example of the first embodiment in a metallic frame is
used as an example for explanation.

[0118] Referring to FIG. 8A, FIG. 8A is schematic top view of a metallic
structure according to an example of applying a fifth embodiment of the
present invention, wherein the first metallic block 110 and the second
metallic block 120 shown in the first example of applying the first
embodiment is disposed in a metallic frame 210.

[0120] From FIG. 8B and FIG. 8c, it can be known that the length 11, the
width w1 of the first metallic block 110, and the predetermined distance
d of this example satisfy the aforementioned equations (1)-(4), and the
metallic structure of this example has good filtering and polarizing
effects.

[0121] It is particularly noted that the aforementioned examples of the
respective embodiments are merely used as examples for explanation, and
do not intend to limit the present invention. Therefore, the applications
of the metallic structures of the present invention are not limited
thereto.

[0122] It will be apparent to those skilled in the art that various
modifications and variations can be made to the structure of the present
invention without departing from the scope or spirit of the invention. In
view of the foregoing, it is intended that the present invention cover
modifications and variations of this invention provided they fall within
the scope of the following claims and their equivalents.

Patent applications by Kuan-Ren Chen, Tainan City TW

Patent applications by NATIONAL CHENG KUNG UNIVERSITY

Patent applications in all subclasses Polarization using a time invariant electric, magnetic, or electromagnetic field (e.g. electro-optical, magneto-optical)